How do I unregister a directory from Java watchservice?

Question

I registered a folder to my watchService:

path.register(watchService, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY);

Later on, I want to cancel this registration. I know that I somehow need to tell the watchService which WatchKey I want to cancel. What's the correct function to accomplish this?

Answer 1

You have the information in the Watchable interface javadoc that provides the method to register a Watchable object (such as a Path instance)

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public interface Watchable

This interface defines the register method to register the object with a WatchService returning a WatchKey to represent the registration. An object may be registered with more than one watch service. Registration with a watch service is cancelled by invoking the key's cancel method.

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So you have just to do :

WatchKey watchKey = path.register(watchService, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY);
...
watchKey.cancel();

Answer 2

The register method returns the WatchKey, as described in the documentation, which has a cancel() method.